Technical Abstract:
This paper presents a vision for developing and promoting hydropedology as a new interdisciplinary science that embraces multiscale basic and applied research of interacting pedological and hydrological processes and their properties in the vadose zone. Landscape water flux is suggested as a unifying focus for hydropedology that is related to storages, pathways, residence times, and spatio-temporal organization of water in the root and deep vadose zones, and through which pedological and hydrological expertise can be better integrated. After illustrating multiple knowledge gaps that can be addressed by the synergistic integration of pedology and hydrology, we suggest twelve scientific hypotheses that require vigorous testing and concerted efforts from pedologists and hydrologists. Among them, six are critical concepts and challenges for advancing hydropedology and for enhancing the prediction of landscape water flux (i.e., a holistic conceptual framework, hierarchical structures, patterns, bridging multiple scales, elegant and robust models, and human impacts), and the other six are related to the unique contributions of hydropedology to the advancement of hydrology and pedology (i.e., soil morphology, genesis, classification, mapping, database, and future advancement of pedology). We then present three interlinked strategies for achieving the stated vision.